1. Field of the Invention
The present invention relates to the cosmetic use of 3-indolepyruvic acid for the protection of the skin against damage caused by oxygen, by the sun and by aging.
In the present society the use of cosmetic products, intended as locally applied preparations for the cleaning, protection, deodorization, perfuming and decoration of the surface of the epidermis, without having any therapeutic effects, has become more and more common. Among the many locally applied preparations great importance has been assumed, especially in recent years, by those products whose object is to protect the skin from damage caused by oxygen, by the sun and by the aging process.
2. Description of the Prior Art
It has been known for several years that oxygen free radicals, when produced by the organism in quantities greater than the capacity for disintoxication with which all living beings are provided, can easily attack the basic cell structures, such as nucleic acids, proteins and membranes, bringing about in the end the death of the cells of, and thus inducing degenerative diseases in all the types of tissue which are attacked. This attack is particularly dangerous in the case of disease of the skin cells.
In a volume published by Raven Press in 1984 ("Free radicals in Molecular Biology, Aging and Disease"), the excessive presence of oxygen free radicals was considered to be the cause not only of the above mentioned diseases, but also of the normal aging to which all living beings are subject.
3-indolpyruvic acid is a known compound per se: its production is cited for example in the U.S. Pat. No. 4551471, in which a process for its enzymatic synthesis is described using the enzyme aspartate amminotransferase, and in the published international application No. WO87/00169, in which a process for the chemical synthesis of said 3 indolepyruvic acid is described using a coupling reaction starting from 1-tryptophan.
Also belonging to the state of the art is the use of 3-indolepyruvic acid for the treatment of diseases of the central nervous system caused by an excess of excitatory amino acids as described in International patent application No. WO88/09789.
It has now been surprisingly found that 3-indolpyruvic acid is a powerful inhibitor of the effects of oxygen free radicals, of exposure to ultra-violet rays and the relative aging of the skin.